Rotary engine



. J. BOLFING.

ROTARY ENGINE.

APPLICATION FILI-:D Au s.9. I9I8.

2 SHEETS-SHEET l.

A. J. BOLFING.

ROTARY ENGINE.

APPLICATION FILED AUG.9,191B.

Patented pr. L55 1920.

:ZJSHEETs-SHEET 2.

A TTOR NE YS iiniTEn sTATEs PATENT oEEioE.

ARTHUR J. BOLFING, OF SAN FRANCISCO, CALIFORNIA.

.ROTARY ENGINE.

Application led August 9, 1918.

To all iff/tom t may concer/L."-

Be it known that l, ARTHUR J. Bonrixe, a citizen ol" the United States,and a resident ot the city and county ot San Francisco, State ofCalifornia, have made a new and useful inventionwto wit, Rotary Engines;and I do hereby declare the Ptollowing to be a tull, clear, concise, andexac description ot the same.

Vhe invention relates particularly to rotary internal expansion engines.

Among the objects of the invention are to provide a true rotary engineadapted to use the expansive power of steam, compressed air and likelluids. Other objects and advantages will appeal' as this descriptionprogresses.

In this specification and the annexed drawings the invention isillustrated in the torni considered to be the'best, but it is to beunderstood that the invention is not limited to such form because it maybe embodied in other orrns, and it is also to be understood that in andby the claims following the description it is desired to cover theinvention in whatever torni it may be embodied.

In the accompanying two sheets olI draw,- ings,

Figure l is a perspective view of a rotary engine constructed inaccordance with this invention, broken away in cross section on the lineI--I F ig. 2 to illustrate the interior construction and arrangement otthe pa Fig. a side elevation ot the same, the upper ii ot the engineabove the axial lin" being shown in cross sect-ion.

S is an enlargwd fragmentary detail and illustratingthc manner otmounting controlling the vanes.

Fig. -l is an end elevation oit the same in cross section taken on theline Ill-IV Fig. 3.

Fig. is a tragmentary detail illustrating the initial entrance ot steamwith respect to the vane.

In detail the construction illustrated in the drawings includes, thehollow shatt l, V[ixed in any suitable base such as the brackets 2secured to a suitable foundation 3. The manner of mounting this shaftwill vary with the application oi' the engine to Specification ofLetters Patent.

Patented Apr. 13, 1920.

Serial No. 249,103.

various uses; in the present case the base 3 an air plane. The hollowshaft l is connected with a source ot power, such as the steam servicepipe el, controlled by the throttle valve 5, ope 1ated by the handle 6.The outer end ot' the shat't l is closed by the transverse wall 'T andterminates in the stud 8.

rfhe stator or stationary element ot the engine has a substantiallyelliptical perimeter l() set eccentric to the axis ot the shat't l; theperimeter l() being parallel with the axis ot this shaft, one segment otthe perimeter from 11 to 12 (see Fig. l) being concentric with the axisot' the shaft and adapted to approximate contact with the rotor orrotating element of the engine. The rotor comprises a substantiallycyliir drical casing 13, having the lateral flanges lie-l5 to which theside plates 16 and 1T are bolted (see Fig. 2). The hubs 18 and l) otthese respective plates are suitabl \v machined to receive theantifriction roller bearing 20 and 2l respectively, interposed betweenthe hubs of these plates and the shatt l, and the stud 8, at oppositesides ot the engine, to provide suitable mountings 'tor the rotarycasing on its axial center, concentric with the axis ot the shaft labout which it is free to rotate. The casing i3 is provided atcircumferential intervals with the sockets 22, in the present instancethree in number, but this number may be increased or decreased inaccordance with the number of phases or cycles it is desired that theoperation ot' the engine may pass through during each revolution.

The rotor is provided with the vanes 23, 2e, 25 having cylindrical heads26 adapted to snugly lit and oscillate within the sockets 22, forming apressure tight contact therein. rllhe bodies ot these respective vanesare lcurved on radii equal to the radius oitl the ing from in front ofthe ends of the vane and to a suitable distance to the rear thereof.

To insure the contact of the inner end of the Yanes against theperimeter 10 of the stator, I pr vide the torsion springs 30 confinedwithin the hollow of the heads 26 of the ifanes. rllhe inner` end 31 ofthe springs engages a hole 32 in the head 26, the opposite end 33 of thespring engages a Yplug 311 rotatable within the sockets 22, and

is provided with a suitable wrench stud for rotating the plug, toincrease or diminish the torsional tension on the spring 30, the tensionbeing lixed by the pin 36 in the plates 16 or 1T and engaging notches 37in the plugs. The plug is covered by the cap 38 screwed thereorer. Thetorsion of the spring 30, and the initial impact of the steamv againstthe vane tends to swing the vane inward against the periphery of thestator, to insure their contact therewith against centrifugal force,friction or any other causes liable to break the contact between thestator and the vanes.

The eccentric relation of the stator to the outer casing leaves acrescent shaped space between these members within the casing. it is thefunction of the Yanes to divide this space into cycles or phasesrepresenting intake, expansion and exhaust.

The inlet nozzle l0 communicates througl the throat l1 with the hollowshaft l, the outlet or mouth of the nozzle being closed by contact withthe interior perimeter of the casing and the vanes passing thereover,during the cutoff cycle or period. The nozzle of a rotary steam engineis a member in which the energy existing as heat in the steam isconverted into kinetic energy or energy of motion. rlhis conversion,when properly carried out, is highly efficient, that is, the proportionof heat converted into work may closely approach the limitingtheoretical value. rlhe cross section of the nozzle is determined by thepressure and quantity of steam to be passed and the amount of heat to beconverted into work; it will therefore vary with certain conditions. Thecross section of the throat determines the steam that can pass with agiven initial pressure. From the narrowest part to the outlet, the crosssection increases in such al way that as the steam continues to expand,there is an approximately uniform acceleration. In the case ot waterthis enlargement of friction would be accompanied by a reduction ofvelocity. But when dealing with steam there is a continual gain in thevelocity of the steam particles and a decrease in density, pressure andtemperature. ln the present instance it is desirable to obtain impact ofthe steam against the vanes as well as 'to utilize its expansive effect,for

quantity oi'V that reason the nozzle l0 is curved to approach as nearlyas may be a tangential delivery at the periphery or outlet against thevanes, to avoid the production of acoustic vibrations and nodes of highand low pressure in the issuing jet. Such disturbances result in steamshock and in a reconversion of kinetic energy into heat, in such a waythat such heat is passed through the engine without doing useful work.To maintain the acceleration of the steam issuing from the nozzle, thecontour of the recesses 27-28-29 are so shaped as to present the leastresistance to the owing steam, compressed air or other Huid issuing fromthe nozzle.

To regulate the cutoff,7 or the points at which the steam issuing fromthe nozzle is permitted to enter the casing, l provide the slidable yplates l13, all, and 45, extending across the width of the casing 13,and following its concentric contour. Each plate is controlled by a wingnut l, threaded onto stud on the plate and jamming against the exteriorperimeter 13 of the casing. For the sake of simplicity in illustration,this elementary form of adjustment is shown. It is obvious, however,that these'plates may be moved in unison by the addition of suitablemechanisms for that purpose.

Referring to Fig. 1, the mouth of the nozzle l0 has just been cut olf bythe edge of the contiguous plate 43. The space A, between the stator,the rotor and the vanes 2a is being filled with expanding steam, whichin 'seeking space within which to expand will advance toward the largerarea B aga-inst the stator, thus pulling or rotating the casing to theright or clockwise as indicated by the arrow, until the vaneY 24 assumesthe position in which the vane 25 is shown, which is approaching thecycle of maximum expansion in the space B. .At the point 10 in theperimeter of the stator 9 the space C between the stator and the rotorbegins to contract, which is the exhaust cycle, the contraction of thespace reachiiw its maximum when the vane has assumed the position of thevane 23, forcing or squeezing the expanded steam through the portsformed in the perimeter or' the stator between the cross bridge au, thatremain merely to give stability to the stator, and to guide the end ofthe vanes passing thereover. The exhaust or expanded steam, forced intothe chamber 19 of the stator, escapes through the crescent shaped space50 surrounding the hollow shaft 1 and extending to the atmosphere orsuitable condensers for reconversion to water, in accordance with theusual practice The inner surface of the vane 23 lying against theconcentric portion 51 of the stator permits the passage of the vanethereacross, meantime effectively sealing theY escape of steam from thenozzle 110, also sealing the cycle A in the operation or" the engine.Vhen the end of the vane 23 passes the opening or mouth of the nozzleett), the steam escaping therefrom into the recess 29 therebehind,adding its Jforce to the spring 30 operating against the vane, forcesthe edge of the vane against the perimeter of the stator as illustratedby the vane 24, the steam escaping into the recess and completelyfilling `the space A, as previously described, until the succeedingAplate '-l assumes the position illustrated by the plate #L3 at which pyriod the steam is again cut oil and expands and exhausts as described.

Should it so happen that the engine should stop on a dead center such asrepresented in Fig. l, after the throttle 5 was closed and no steam wasissuing through the nozzle e0, it would be manifestly impossible tostart the engine. To overcome this diiiiculty l provide the by-pass 52,communicating through the longitudinal hole 53 with a steam pipe 54C,controlled by the 'alve 55, so that steam may be introduced into thespace past the check valve 5o, 'for moving the rotor past the deadcenter until it attains suiiicient momentum to carry it over this centerin the succeeding revolutions. The check valve 5G prevents back pressurethrough the pipe 53.

The sides of the stator contact with the plates 16 and l? and preventleakage of steam at these points, all points oi: :approximate contactbetween the stator and the rotor being effectively sealer., pressuretight, by the introduction of suitable lubricant with the steam in theusual manner. To further insure proper sealing, l introduce thelaminated packing 57 and 58 on oppoite sides of the engine adjacent tothe bearings 2O and 2l. Lost motion in the bearings 2O and 2l may betaken up by the running nuts 59. threaded on the shaft and jammed by thelock nuts 60 and 6l in the usual manner. These bearings are protected'by the caps 62 and 63, the former fixed to the plate 1G and engagingtlie'hol low shaft against which it is packed by the stuiiing gland 64C,for thc purpose of retaining lubricant within the bearings. The cap 63pei-tr ins a similar function and is iixcd to the plate 1 7 over the endo1 the shaft, like wise iin-losing the bearing 2l for the purpose ofretaining lubricant.

The relative position of parts shown in F 5, illustrates the liftingaction of the steam entering the recess 27, behind the end of the vaneand forcing it against the perimeter lO of the rotor. indicated by thearrows.

Centrifugal force can be taken advantage of to maintain the contactbetween the vanes and the rotor, by the counterweight S0 rlxed to thevane on the opposite side of its pivoted center and projecting through aslot in the rotor. rllhe outward throw of the counterweights swingingthe ends of the vanes inward, as shown in Fig. 5.

Modifications within the purview of this invention will suggestthemselves to those skilled in the art in adapting it to specialpurposes.

Having thus described this invention, what l claim and desire to secureby Letters Patent is:

l. A rotary engine comprising a stator set eccentric to the axis of theengine and having a nozzle therein; a rotor inclosing saidstator,vconcentric with said axis and circumferentially contacting withsaid stator and closing said nozzle, and having recesses therein;adjustable cutol3 means interposed between said rotor and statorcontiguous to said nozzle and said recesses; vaines interposed atintervals between said stator and rotor; and means for introducing anexpansive medium through said nozzle, and exhausting it from betweensaid vanes.

2. A rotary engine comprising a stator; a rotor inclosing saidstatorandhaving vane sockets therein; vanes having hollow headspivotally engaging said sockets, with their opposite ends bea-ringagainst said stator; torsion springs within said heads having one endengaging said vane and the other engaging said rotor and adapted tonormally hold said vanes in contact with said stator.

3. A rotary engine comprising a iixed hollow shaft; a stator. on saidshaft; a rotor inclosing said stator, set eccentrical'ly thereto andcircumterentially contacting therewith; curved vanes pivoted in saidrotor and adapted to pass the contact between said rotor and stator;spring means within said vanes tor normally holding the same in contactwith the stator; perimetrical recesses in said rotor contiguous to saidvanes, means for introducing an expansive medium ahead of said firstmentioned inlet and an exhausting outlet of substantially the same widthas the stator.

Al. A rotary engine comprising a fixed hollow shatt;`a stator eccentricon said shaft having a nozzle therein opening into aid shaft and throughthe perimeter of said stator of substantially the same width as thestator: a rotor having perimetrical recesses and inclosing said statorconcentric with said shaft and contacting with said stator contiguous tothe outlet of said nozzle` curved vanes pivoted in said rotor andadapted to concentrically pass the said contact between said stator androtor and extending over said recesses; means for introducing anexpansive medium through said hollow shaft and'nozzle; an auxiliaryinlet for introducing an expansive medium ahead of said nozzle, and asuitably disposed yfrom the engine.

bridged chamber within said stator connected with means for exhaustingsaid medium 5. A rotary engine comprising a fixed hollow shaft; a statoreccentric on said shaft and substantially in perimetral contour andhaving va nozzle therein opening into said shaft and through theperimeter of said stator, a rotor having perimetrical recesses andinclosing said stator, concentric with said shaft and contacting withsaid stator contiguous to the outlet of said nozzle; curved vanesvpivoted in said rotor and adapted to concentrically pass the saidcontact between said stator and rotor and extending over said recesses;means for introducing an expansive medium through said hollow shaft andnozzle; said nozzle so shaped as to impartan impact as well as expansiveforce to said expansive medium, an auxiliary inlet for introducing anexpansive medium ahead of said nozzle and means for exhausting saidmedium from the engine.

6. A rotary engine comprising a rotor and stator; vanes pivoted in saidrotor and bearing against said stator; means for introducing anexpansive medium between said vanes comprising an inlet port extending'substantially across the full width of the stator, an auxiliary inletfor introducing an expansive medium ahead of said first mentioned inletand means for exhausting said expansive medium comprising a portextending substantially across the full width ofthe stator and occupyingapproximately one fourth of the peripheral area of said stator.

"7. A rotaryV engine comprising a fixed hollow shaft; a stator on saidshaft; a rotor inclosing said stator, set eccentric thereto andcircumferentially contacting therewith, curved vanes pivoted in saidrotor and adapted to passthe contact between said rotor and stator;perimetrical recesses in said rotor contiguous to said vanes; means forintroducing an expansive medium between said vanes; an auxiliary inletfor introducing an expansive medium ahead of said first mentioned inlet;and an exhausting outlet of substantially the same width as the stator.y

8. A rotary engine comprising a fixed hollowshaft; a stator on saidshaft; a rotor inclosing said stator, set eccentric thereto andcircumferentially contacting therewith; curved vanes pivoted in saidrotor and adapted to pass the contact between said rotor and stator;perimetrical recesses in said rotor contiguous to said vanes; an inletfor introducing an expansive medium between said vanes adjacentsaidpoint of contactof the stator and rotor; adjustable cutoff meansinterposed between said rotor and low shaft; a stator on said shaft; arotor inclosing said stator, set eccentric thereto and circumferentiallycontacting therewith; curved vanes pivoted in said rotor and adapted topass the contact between said rotor and stator; perimetrical recesses insaid rotor contiguous to said vanes; an inlet for introducing anexpansive medium between said vanes adjacent said point lof contact ofthe'stator and rotor; adjustable cutoff means interposed between saidrotor and. stator contiguous to said inlet and recesses and means insaid stator for exhausting said expansive medium; an auxiliary inlet forintroducing an expansive medium ahead of said first mentioned inlet;adjustable cutoff fmeans interposed between said rotor and statorcontiguous to said inlet and recesses and means in said stator forexhausting said expansive medium. y

10. A rotary engine comprising a rotor and stator; vanes pivotedA insaid rotor; spring means within said vanes for normally holding the sameagainst the stator; means for introducing an expansive medium betweensaid vanes comprising an inlet port extending substantially across thefull width of the stator; an auxiliary inlet for introducing 'anexpansive medium ahead of said first mentioned inletand means forexhausting saidV expansive medium-comprising a port extendinglsubstantiallyv across the full width of the stator and occupyingapproximately one fourth of the peripheral area of the stator.

11. A rotary engine comprising a fixed hollow shaft; a stator on saidshaft; a rotor inclosing said stator, set eccentric thereto andcircumferentially contacting therewith; curved vanes pivoted in saidrotor and adapted to pass the :contact between said rotor and stator;spring means within said vanes for normally holding the same in contactwith the stator; perimetrical recesses in said rotor contiguous to saidvanes; an inlet for introducing an expansive medium between said vanesadjacent said point of contact of the stator'and rotor; adjustablecutofi' means interposed between said rotor and stator contiguous tosaid inlet and recesses and means in said stator for exhausting saidexpansive medium.

ln testimony whereof I have hereunto set my hand at San Francisco;California, this 27th day of July, 1918.

A. J. BOLFING.

In presence of- A. J. HENRY, BALDWIN VALE.

